Inorganic dissolution accelerator making metal or inorganic substance water-soluble

ABSTRACT

The invention provides an inorganic dissolution accelerator used for obtaining a water-soluble inorganic compound(s), high in concentration and containing a large solid content, which accelerator is prepared by making one or more compounds selected from fluorides, mineral acids, mineral “ous” acids and salts thereof, and boric acid compounds, all either natural or synthetic, coexist with an alkali metal and/or substance containing an alkaline metal, and is able to transform metals and inorganic substances present in water, either natural or synthetic, containing as the main component silicon Si, aluminum Al, and/or boron B, into amorphous highly water-soluble inorganic compounds having the solubilities equal to, or larger than those well known in the art.

TECHNICAL FIELD

The present invention relates to an inorganic dissolution acceleratorwhich makes metals and inorganic substances water-soluble, the powderthereof and a production method of the powder, and relates to amorphoushighly water-soluble inorganic compounds (amorphous water-solubleinorganic compound enabled to dissolve in water in a highconcentration), amorphous highly water-soluble inorganic compounds to betransformed into water-resistant hardened substances, inorganic moldedprecursors, noncombustible inorganic foams and rapid heat curecompositions, all based on the above mentioned inorganic dissolutionaccelerators and powders thereof; and more specifically, the presentinvention relates to a dissolution accelerator that makes the metals orinorganic substances, present in water and containing silicon Si,aluminum Al or boron B as the major component, dissolve in the water ofa concentration not lower than the solubility well known in the art.When amorphous highly water-soluble inorganic compounds of metals andinorganic substances are realized and are further converted into thewater-resistant hardened substances, then solvent-free inorganic foamsthat can be used as coating compositions, molded materials and heatinsulating materials are obtained, and for these compositions andmaterials, various types of applications including building materialsand the like are expected.

BACKGROUND ART

The petrochemical products are convenient when being used, but producethe exhaust gas pollution when burnt, and give rise to the environmentalhormones. Accordingly, at present, the inorganic products are demandedwhich can substitute for the petrochemical products, reduced to naturewhen dumped and/or disposed of, and pollution-free even when burntand/or dumped. The pollution-free inorganic substances that cansubstitute for synthetic resins should be solvent-free inorganicpolymers; the inorganic polymers become possible in the form of highlywater-soluble inorganic compounds, but there have been no methods formaking metals and inorganic substances take the forms of solvent-freeaqueous high concentration solutions. It has been difficult that metalsand inorganic substances, which are insoluble or hardly soluble inwater, are made to be water-soluble in high concentrations. When theresearch and development is considered for searching for inorganicpolymers, it has been necessary to convert crystalline materials intoamorphous materials to obtain high concentration aqueous solutionthereof.

The present inventors have disclosed that the anhydrite (CaSO₄) calcinedwith added fluorides or boric acid based compounds acts to acceleratethe elution of Ca or SO₃ at normal temperatures and, when heated, actsto accelerate remarkably the elution of the alumina component even ifthe gypsum component is in a supersaturated condition, and accordinglyacts to make the cement be quickly hardened like thermosetting resins,in U.S. Pat. No. 3,664,854, U.S. Pat. No. 3,915,724, Japanese PatentPublication No. 57-022907, “Cement Admixture Composed of SpecialAnhydrite,” and Japanese Patent Publication No. 59-032416, “HeatHydraulic Bonding Material and Molding Method Thereof.” Additionally,the present inventors have proposed that silanol salts, fluid even inhigh concentrations, are generated, but sodium silicate is not producedby the interfacial reaction in water between the solid metal and highconcentration alkali metal with the coexisting compounds of boric acidand hydrofluoric acid, in Japanese Patent Publication No. 7-14801,“Aqueous Film-Forming Inorganic Compound and Method for Producing theSame.”

In addition to the above, in Japanese Patent Laid-Open No. 8-73212,“High Concentration Boric Acid Compound and Composition forFireproofing/Fire Resisting Use Containing the Same and Binding Materialand Fireproof/Fire-Resistant Material Using the Same,” the presentinventors have disclosed the finding that even such boric acid compoundsthat are low in water solubility can be high concentration boric acidcompounds exceeding by far the solubility of 4 wt % well known in theart, when warmed by blending and with the coexistence of mineral acidsor mineral “ous” acids or salts thereof.

The above described fluorides, mineral acids or mineral “ous” acids orsalts thereof and/or boric acid compounds, which are all reaction aids,require the concomitant use of chelating agents such as citric acid andother carboxylic acids for the purpose of accelerating the dissolutionof cement components, and require the concomitant use of chelatingagents and surfactants for the purpose of accelerating the dissolutionof boric acid compounds. Additionally, for production of the aqueousfilm-forming inorganic compounds, the above described reaction aids havebeen assumed to be the catalytic reaction aid for the interfacialreaction with the solid metal in which the high concentration alkalisolution in a supersaturated condition compensates the fraction of thealkali component consumed by the chemical reaction, according to thetheory of solubility product, in the lower part of the reaction vessel.Accordingly, the reaction proceeds under the condition of theautoconvection generated under the still-standing reaction withoutstirring, and is thereby under the condition of no forced stirring formixing.

As for the production conditions, the intended rise of the blendingratio utilizes the increased amount of alkali metal, resulting in astrongly alkaline product. Thus, it has been required to establish amethod that increases the yield, and moreover, raises the Si/Na ratiofor actualizing the water resistance.

For the purpose of transforming metals and inorganic substances intohigh concentration aqueous solutions, it is necessary to transformcrystalline materials into amorphous materials. Such metals andinorganic substances that can be easily converted, in the amorphousstate, into high concentration solutions include silicon Si, aluminumAl, borax, and boric acid. In order to dissolve these substances,chemical dissolution accelerators, and physical dissolution acceleratingmethods of warming, forced stirring and mixing, and the like have beenrequired. Modern mass production methods adopt forced operations such asphysical contact and stirring and the way of accelerating reactions byheating; in order to accelerate the dissolution rate, the abovedescribed physical dissolution accelerating methods are needed to beused in combination with other methods, but the dissolution accelerationhas been difficult when based only on the chemical reaction conditionsand when agglomerate raw materials such as metallic silicon are used.

Additionally, the dissolution accelerator should not be left as theundissolved residue, but should be a reactant component that forms thecompound.

The production of the above described aqueous film-forming inorganiccompound is based on the reaction in which the reactant base materialsare allowed to stand still and the reaction is commended to theautoconvection, and hence the film formation tends to occur on thesurface of the water; accordingly the evaporation of the bulk water isprevented and thereby the concentration increase rate is slow so that ittakes long time to reach a high concentration and it has been necessaryto adopt an additional concentration method.

As for the production of the above described water-soluble film-forminginorganic compound, a method has been proposed in which alcohols and amineral acid are added, and then the alcohols are removed to increasethe solid content; however, when the pH is made to be 12 or lower andthe above described alcohols are added, the yield is poor, while whenthe pH is made low from the beginning, precipitate is generated whenstored, and hence it has been impossible to obtain a compound containing60% or more solid content by adjusting without restraint the pH to anarbitrary low value.

An object of the present invention is to obtain a water-solubleinorganic compound that is high in concentration and large in the solidcontent contained therein. Even when adopting a method in which alcoholswith acids added are used for treatment and the yield of the residualsolid content is thereby increased, a low starting concentrationnaturally results in a low yield. In other words, unless the startingconcentration of the aqueous inorganic solution among others is madehigh, no products have been able to be obtained in high yields which arehigh in concentration and large in the contained solid content. With thepH values of 11.5 or lower, although transparent solutions are able tobe formed which are 30% or more in the concentration of the solidcontent, precipitation occurs when stored, and there is a trend towardending up with the decreased concentrations of the solid content in theaqueous solution.

To an alkaline metal, one or more compounds, selected from the groupconsisting of fluorides, mineral acids and mineral “ous” acids and thesalts thereof, and boric acid compounds, are added to make an inorganicdissolution accelerator; then the inorganic dissolution accelerator isadded as dissolution accelerator to an aqueous solution which is chargedwith a metal or an inorganic compound, insoluble or hardly soluble inwater, and is warmed to 40° C. or above; and in this way, it has beenpossible that a metal or an inorganic substance, either natural orsynthetic and either insoluble or hardly soluble in water, istransformed into an amorphous highly water-soluble inorganic compoundhaving a solubility not smaller than that well known in the art. Bymaking the concentration further higher or by increasing theconcentration of the metal component, the hardened substance formed byheating can also be made insoluble in water. The amorphous highlywater-soluble inorganic compounds form inorganic polymers with filmforming property, and thus when heated, boil with foam to become plasticfilm, with the contained water acting as foaming agent; thus,solvent-free noncombustible inorganic foam precursors and heatinsulating materials have been able to be commercialized.

Additionally, the present invention has achieved a highly water-solubleinorganic compound on the basis of the attempted physical treatmentsincluding heating, stirring and/or mixing and using an inorganicdissolution accelerator, but neither by using the sol-gel method nor byusing surfactants and catalysts. Water-soluble materials have such aproperty of redissolution in water even after having been hardened, butthe water-soluble inorganic compounds, despite of being water-soluble,are needed to be made insoluble by hardening. If solvent-free inorganicpolymers could be commercialized, the resources could be made recyclableresources that are reducible to the nature in a pollution-free manner.Besides, if inorganic heat insulating materials can be produced, bothenergy saving and resource saving can be achieved in a combined manner.

Conventional inorganic aqueous solutions have a drawback thatdehydration and hardening operation thereof is accompanied by waterreabsorption. Only when a high concentration inorganic aqueous solutionexhibits water resistance when hardened, although it is aqueous, thepracticability is imparted thereto.

According to the prior art, it has been necessary to use chelatingagents, and various surfactants are concomitantly used for dissolutionacceleration.

An examination of the hitherto developed achievements indicates that analkaline metal such as Na or Ca is always needed as a reactant componentwhen a metal or an inorganic compound is dissolved, irrespective as towhether or not chelating agents and surfactants are used. It is wellknown in the art that borax, as represented as Na₂B₄O₇.xH₂O, contains analkali metal, and some natural mineral borax from Turkey containsalkaline earth metals (Ca, Mg). As disclosed in the above describedJapanese Patent Publication No. 7-14801, it has been found that boraxdoes not dissolve in water by nature in a concentration of about 4 g/100g water or more at an ambient temperature, and dissolves in aconcentration of about 8 g/100 g water even at 100° C., but borax candissolve in warm water in the presence of an alkali metal withoutproducing any undissolved matter.

In the reaction described in the above described Japanese PatentPublication No. 7-14801, the presence of metallic silicon Si andmetallic aluminum Al is the necessary condition; however, the borax isnot precipitated as the insoluble pentahydrate but a transparentsolution can be obtained when the metallic silicon is removed, nosurfactants are added to the water, borax, sodium fluoride and causticsoda are added, and then heating is made. Even when a salt of a mineral“ous” acid such as sodium sulfite, sodium nitrite or sodium phosphite isused in place of sodium fluoride (commercially available industrialsalts of 98% or above in purity are used), heating results in completedissolution and a transparent solution can also be obtained.

Replacement of caustic soda with caustic potash or lithium hydroxideleads to similar dissolution. Borax, sodium fluoride and caustic sodaact as dissolution accelerators for metallic silicon.

The reaction conditions in the above described Japanese PatentPublication No. 7-1801, in which the quantities of water, metallicsilicon, aluminum, and alkali metals are made constant and the quantityof sodium fluoride is increased, result in an increase of the specificgravity as observed after a certain elapsed time.

The metallic silicon used is a 99% pure Chinese-made product, and thealuminum used is a commercially available 99% pure aluminum wire. Thereis no particular limitation for the purity, but it is advisable to usehighly pure products because otherwise the impurities contained remainas residuals.

In the preceding reaction, the solid content is increased, but the pHvalue becomes high when the quantities of water, metallic silicon andsodium fluoride are maintained constant, and the quantity of causticsoda is increased. Thus, a method comes to be required which gives riseto a high yield and yields a low pH product.

Under the preceding reaction conditions, the specific gravity yieldsvary in the order of sodium sulfite>sodium nitrite>sodiumfluoride>borax>sodium phosphite when the quantities of water, metallicsilicon and caustic soda are maintained constant, a certain amount ofsodium fluoride and sodium sulfite, sodium phosphite, sodium nitrite orborax is added; and the specific gravities are measured after a certainelapsed time.

In the above described reaction, the reaction is conducted under theconditions that warming is made under the bottom of the vessel andstirring is made, but still-standing interface reaction between metallicsilicon solid and a highly concentrated solution of alkali metal is notconducted on the bottom of the reaction vessel under the conditions thatsodium fluoride, borax or a salt of a mineral “ous” acid are added.

The reaction vessel is filled with water, and sodium fluoride is put inthe water under stirring without dissolution, but addition of anhydrousborax and boric acid, under the conditions that the solution ismaintained alkaline and heating under stirring is made, leads to anapparently transparent solution. If the preceding sodium fluoride ormineral “ous” acids are absent, residual undissolved matter, dispersedand suspended, can be visually observed even under heating and stirring.

In the preceding test, the produced solution is weakly alkaline, andaddition of 86% phosphoric acid converts the solution to a weakly acidicsolution which can maintain transparent dissolution condition over along period of time.

In the above described reaction, a transparent aqueous solution can beobtained, even when sulfurous acid, nitrous acid, phosphorous acid, andthe salt thereof are used in place of sodium fluoride, and even whensulfuric acid, nitric acid and hydrochloric acid (all being of thecommercially available industrial grade) in place of phosphoric acid.

The object of the present invention is to create a highly water-solubleinorganic compound.

DISCLOSURE OF THE INVENTION

In claim 1 of the present invention, one or more compounds selected fromfluorides, mineral acids, mineral “ous” acids and salts thereof, andboric acid compounds, all either natural or synthetic, are made tocoexist with an alkali metal and substances containing alkaline metals,and an inorganic dissolution accelerator is thereby prepared; and theuse of the inorganic dissolution accelerator makes it possible thatmetals and inorganic substances present in water, either natural orsynthetic, containing as the main component metallic silicon Si,metallic aluminum Al, or boron B, are transformed into amorphous highlywater-soluble inorganic compounds having a high concentration not lowerthan the solubility well known in the art.

Claim 2 of the present invention claims the amorphous highlywater-soluble inorganic compound according to claim 1, which issynthesized by using the dissolution accelerator of claim 1 and bywarming to 40° C. or above for dissolution acceleration, so that themetal or inorganic substance in the preceding claim, either natural orsynthetic, is made to have a concentration not lower than the solubilitywell known in the art.

Claim 3 of the present invention claims the amorphous highlywater-soluble inorganic compound according to claims 1 and 2 to betransformed into a water resistant hardened substance when heated, whichis produced as follows: the highly water-soluble inorganic compound ofclaims 1 and 2, with the pH value of 12 or above, is mixed with alcoholscontaining an added mineral acid, then the contained water and thealcohols are removed, the pH is made to be 11.5 or lower, and either thesolid content is made to have a high concentration of 50% or higher orcyanuric acid or melamine isocyanurate is added.

Claim 4 of the present invention claims the amorphous highlywater-soluble inorganic compound according to claims 1 to 3 to generatea water-resistant hardened substance when heated, which is produced asfollows: the amorphous highly water-soluble inorganic compound of claims1 to 3, in which the main component of the metallic component is Si orAl, is adjusted so as to have the metallic component 2.5 times or morehigher in molar ratio than the alkali metal component by further addingan amorphous component containing metals.

Claim 5 of the present invention claims a solvent-free inorganic foamaccording to claims 2 to 4, which is produced as follows: the amorphoushighly water-soluble inorganic compound of claims 2 to 4 is exposed toan arbitrarily selected temperature between 100° C. and 900° C. to beheated for a certain period of time, thereby dehydrated by evaporationresulting in boiling with foam, and thus transformed into a plasticizedfilm-forming substance which is further formed into a film to have apressure resistance strength under evaporation.

Claim 6 of the present invention claims an inorganic molding precursoraccording to claim 5, which is made sheet like or granular by air dryingor heating the amorphous highly water-soluble inorganic compound ofclaim 5 so as to make the water content fall within 30%, and is to beboiled with foam, to be plasticized to form film and to form asolvent-free inorganic foam when heated.

Claim 7 of the present invention claims the amorphous high concentrationinorganic water-soluble compound according to claims 1 to 3, which isproduced by adjusting, within 4 to 9 without restraint, the pH of thehighly water-soluble inorganic compound of claims 1 to 3, produced byadding a dissolution accelerator and in which the main component of themetallic component is a B compound.

Claim 8 of the present invention claims a rapid heat cure compositionwhich is produced by adding the inorganic dissolution accelerator ofclaim 1 to portland cement or alumina cement.

Claim 9 of the present invention claims a powder of the amorphous highlywater-soluble inorganic compound of claims 1 and 2 which is produced bywarming the above described inorganic compound to 300° C. or above andis dehydrated by heating through spraying with a nozzle warmed so as tomake the temperature at the target be 150 to 300° C., or a powder whichis produced by heating to 150 to 300° C. and thereby dehydrating theabove described amorphous highly water-soluble inorganic compound,followed by pulverizing.

Claim 10 of the present invention claims a fire-retardantorganoinorganic composite foam and a production method thereof, whichfoam is produced by adding, in 20 wt % or more, the amorphous highlywater-soluble inorganic compound of claims 1 and 2 to a polyol compoundas the main component of urethane, together with a deoxidizing fireretardant, and furthermore by adding a curing agent to be highly foamed,and is characterized by the cushion property thereof.

Claim 11 of the present invention claims a fire-retardantorganoinorganic composite foam and a production method thereof, whichfoam is produced by adding, in 100 wt % or more relative to the sumamount of the main component of urethane and the curing agent, thepowder of the amorphous highly water-soluble inorganic compound ofclaims land 2, containing the boron B component as the main component,and water or the above described highly water-soluble inorganic compoundcontaining the 40% or more solid content, and which foam is equal to orlarger in foam volume than the used urethane components.

As described above, the present invention has made it possible totransform insoluble metals and inorganic substances into water-solublecompounds in high concentrations. The fact that crystalline inorganicsubstances acquire water solubility indicates that the crystallinesubstances are transformed into amorphous substances, and there has beenconfirmed a phenomenon that heating to accelerate the reaction resultsin film formation. According to the conventional methods, a phenomenonoccurs in which a film is formed on the surface of the water in thereaction vessel, thus preventing evaporation of the aqueous solution andadversely affecting the productivity in the process for attaining highconcentrations. In order to overcome this problem, steadily stirring isnecessary to be conducted in the production process. The use of thedissolution accelerator of the present invention makes it possible toprevent the surface film formation and to attain high concentrations byheating under stirring.

Even when the solid content (the residual amount by weight obtained from5 g heated at 105° C. for 3 hours with an electric furnace) of theproduced inorganic water-soluble compound amounts to 30%, dehydrationoccurs on addition of alcohol and the component corresponding to thesolid content of 45% is esterified to remain; accordingly, aqueousalcohol containing excessive water is removed and a highly water-solublecompound is obtained which has a high molecular weight. The alcoholsable to be used include various alcohols with various C number fallingin the range from monohydric to polyhyric alcohols such as methylalcohol and glycerin.

When the amount of the alkali metal as the reaction component isincreased, the reaction yield can be increased, but the pH of theproduct becomes high. In this connection, instead of the use of anacidic substance to be simply added to the product for the adjustment,the use of an alcohol mixed with an acid does not destroy the reactioncomposition and leads to a product that is low in pH and high inconcentration.

The amount of the acid added to the alcohol is recommended to be lessthan 10% by weight, because the mixing with the weight ratio of 15%provides so strong an acid as to destroy the water-soluble inorganiccompound when mixed therewith. Additionally, an appropriate mixingamount of the above described water-soluble inorganic compound is withinthree times by weight the amount of the alcohol-acid mixture.

Amorphous SiO₂ is solubilized in an alkaline substance such as causticsoda. Calcined feldspars, zeolite and diatomite can be regarded asamorphous silica, and among others the substances containing amorphoussilica such as pozzolan and glass can also be used. The above describeddissolution accelerator of the present invention contains alkali metalsas constituent, and is transformed, on addition of amorphous silica,into Na₂SiO₃ when heated, and hence into a silica supersaturatedsubstance in which the ratio, SiO₂:Na₂O, of the high concentrationaqueous inorganic compound becomes 3 or more, and accordinglytransformed into an insoluble hardened substance. Silicasol becomes gelimmediately after mixing, but amorphous silica does not coagulate bymixing, thus giving a period of working life, and is involved in areaction when warmed so that it has characteristics of a hardeningagent. If the metallic component is aluminum, calcined clay and bauxitedisplay similar effects. More specifically, it has become possible thatwhen amorphous silica or alumina is added to the high concentrationaqueous inorganic compound, the obtained mixture is not hardened atnormal temperature, but is hardened when heated and forms awater-resistant hardened substance.

The effects of the measures for overcoming the problems of the presentinvention were confirmed on the basis of the following methods.

(Method <1>)

(Step 1) A stainless steel vessel was placed on a gas stove and wascharged with 600 cc of water.

(Step 2) The water of the vessel was added with 150 g of boraxdecahydrate (99% pure) manufactured by BORAX, Inc., USA, and stirred,but the borax was not dissolved, and heating yielded an apparentlytransparent solution. A drop of the solution was placed on a slide glassand cooled, and then brilliant crystalline appearance came back.

(Step 3) The above described solution, in a heated condition, was addedwith 10 g of sodium fluoride (Hashimoto Kasei Co., 99% pure) andstirring yielded a transparent solution. A drop of the solution wasplaced on a slide glass and cooled, and then crystalline substance likethe above was found to remain.

(Step 4) Heating was continued, 10 g of caustic soda manufactured byAsahi Glass Co. (99% pure) was put in and mixed. A drop of thetransparent solution was placed on a slide glass and cooled, and thenthe crystalline substance was not found, but transformation into anamorphous substance was found.

(Step 5) Successively 120 g of boric acid (manufactured by BORAX, Inc.,99% pure) was put in and mixed under stirring. A drop of the transparentsolution was placed on a slide glass and cooled, and then a transparentcoating film was obtained.

The pH thereof was 8.5. Without using either a chelating agent or asurfactant, the solubility of crystalline boric acid/borax became 270g/600 g of water=45% in contrast to that well known in the art of about5 g/100 g of water.

FIG. 1 shows an X-ray analysis chart for the high concentration aqueousinorganic compound according to the above described method <1>. Thechart is broad and shows no crystal peaks, indicating that the samplewas amorphous. The measurement was made by Shimadzu Techno-Research Inc.

The measure for overcoming the problem of the present invention has beenfound to overcome the problem, without adding either a chelating agentor a surfactant to crystalline borax/boric acid, but using alkalimetals, and sodium fluoride, mineral acids, mineral “ous” acids or saltsthereof for inorganic dissolution accelerators provided by theinventors.

Additionally, it has been found that the use of alkali metals (Na, K,Li) that are strong alkali and the addition of acidic substances (boricacid, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid) donot lead to coagulation, and the pH is adjustable.

(Method <2>)

An industrial ethyl alcohol added with hydrochloric acid, sulfuric acid,nitric acid and phosphoric acid in 1 to 2 wt % was prepared, the aqueousinorganic compound solution prepared according to the above describedmethod, of pH 12.4 and a specific gravity 1.42, was added to the ethylalcohol, and the bleeding containing alcohol was removed; then the pHbecame 11 or lower and the yield was obtained which reached 70 to 90 wt% of the put in amount of the above described aqueous inorganic compoundalthough some water content was included. In a previous invention,flexibility was lost when the pH was made to be 11 or lower, but theproduct of the present invention was transformed into a flexiblematerial when warmed to 70° C. or lower.

Diatomite was calcined at 1,000° C., and cooled to prepare amorphousSiO₂, which was mixed in the ratio of 10 wt % according to either theabove described method <1>or <2>, resulting in no coagulation. Thesolution was transferred into a paper cup and heated for 3 minutes in a500 W microwave oven to yield a hardened substance. Water was pouredinto the cup to the level above the interface and observation was made;however, neither softening nor collapse was found in three days and thusattaining the water resistance.

Apiece of copy paper was dipped into the aqueous inorganic compoundbased on the above described method <1>, taken out and dried. The pieceof copy paper was not discolored because the solution was neutral, had aflat and smooth surface, had absolutely no powder on the surface, hadflexibility, and moreover, was carbonized but not burnt with flame whenignited. Thus, it was possible to confirm that the aqueous inorganiccompound is a fireproofing agent without discoloration.

(Method <3>)

A stainless steel vessel was charged with 600 kg of water warmed to 40°C., a cage containing 97% pure metallic silicon of 10 mm or less ingrain size was put in, and then a mixture of 15 kg of caustic soda and10 kg of borax mixed with 5 kg of sodium fluoride was put in. Thereaction occurred more rapidly and vigorously than that at normaltemperature, yielding an amorphous highly water-soluble inorganiccompound of 12.6 in pH and 1.47 in specific gravity. In 100 g of thecompound, 2 to 30 g of the above described soluble silica and glass weremixed; the mixture was placed in a crucible and heated to a temperaturebetween 300° C. and 1,000° C. in an electric furnace, yielding varioustypes of foams of 0.07 to 0.3 in specific gravity. Among these trialproducts, water resistance was found to be generated when the content ofthe above described mixture was made to be 3 g or more and heating wasmade at a temperature of 300° C. or above.

The phenomenon that is observed when the amorphous water-solubleinorganic compound of the present invention is heated to be dehydratedand become viscous and to boil with foam is absolutely similar to thephenomenon observed in caramelizing sugar in which sugar, an organicpolymer, is melted in hot water, is heated to be dehydrated, becomeviscous and boil with foam, is then added with sodium bicarbonate andallowed to stand with heating stopped to yield a sugar cake plasticizedwith a surface film formed and increased in volume, and left to becooled so as to be solidified with foam. In the present invention wateris gasified to work as a foaming agent.

When the present invented product was either observed on a hightemperature microscope or subjected to the FTIR analysis, the exhibitedphenomenon was similar to the above described; around 600° C., the peakof opal was confirmed, ensuring the phenomenon.

To 10 cc of industrial ethanol, 2 g of hydrochloric acid (38%) wasadded, and then 25 g of the amorphous highly water-soluble inorganiccompound according to the above described method <3>was added and mixed;thus, the pH was decreased to 10.8 and the plasticity was lost, but whenwarmed, plasticity was generated so as to form a substance as soft asboiled rice cake; 10 g of the substance was put in a paper cup andheated in a 500 W microwave oven for 3 minutes to yield a foam of 0.15in specific gravity.

It has been found that even when the plasticity is lost owing to the pHdecreased to 11 or lower by adding alcohol containing acid, reheating atlow temperatures can yield a product provided with plasticity.Accordingly, sheets of molded precursors, SMC and foam precursors can bemanufactured, and can be cut to be granulated, yielding foam precursorgranules.

Either the strongly alkaline product of pH 12.6 of the above describedmethod <3>or the preceding acid-alcohol treated product of pH around 11can be kneaded with cyanuric acid and melamine isocyanurate in 1 to 20wt %. Consequently, it has been found that the stretchability isincreased to a magnitude comparable to those of caulking materials at anambient temperature, and when dried, a tensile strength similar to thatof rubber is generated. When heated, plasticity is generated, yielding afoam provided with a certain strength. When heat-resistant fibers aredispersed, high strength FRC is obtained.

The above described conventional techniques based on the use ofsurfactants and chelating agents can hardly stabilize the colloidsolutions of the amorphous highly water-soluble inorganic compounds thatutilize boric acid and borax as raw materials; as has been previouslyobserved at low temperatures, there occurs such a phenomenon that nocolloid balance tends to be established and hence precipitation occurs,but the use of the inorganic dissolution accelerator of the presentinvention permits the production of stable alkaline solutions, andaddition of mineral acids to these solutions allows the production ofstable solutions in which the pH values are easily adjusted withoutrestraint from the alkaline region to the acidic region.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the X-ray analysis chart for a highly water-solubleinorganic compound based on a method <1>.

FIG. 2 shows the X-ray analysis chart for a product of Example A inExample 8.

FIG. 3 shows a graph representing the relation between the heatingtemperature and the amounts of the eluted components in a calcinedanhydrous gypsum CaSO₄ doped with CaF₂ in 1%.

BEST MODE FOR CARRYING OUT THE INVENTION

Description will be made below to demonstrate the operation and effectsof the present invention on the basis of the following Examples.

EXAMPLE 1

The following experiment was performed under the condition that theamount of the inorganic dissolution aid of the present invention was setat 10 g for each run, which was dispersed in 100 cc of water to preparea 10% solution of an inorganic dissolution accelerator; representativeexamples of the components included the following [sodiumfluoride:caustic soda] ratio sets: [1:9] in Case A, [5:5] in Case B, and[8:2] in Case C.

The 10% solution of the inorganic dissolution aid A (30 g, pH 13) waswarmed to 40° C., the amount of boric acid was increased in the order of3 g, 6 g (3+3), 9 g (6+3), and then the solution was transparent in anycase, and the solubility reached 9/30=30%; when further increased to 12g (9+3) and warmed to 70° C., and then increased to 15 g, the pH became6.6 and a transparent solution was obtained. The solubility of boricacid was found to be 15/30=50%. In contrast to the case of boric acid,the added amounts of sodium fluoride and caustic soda were respectivelyonly 0.006 to 0.0533 wt % and 0.06 to 0.0133 wt %. The amount of theinorganic dissolution accelerator was 20 to 100% in relation to theamount of boric acid.

EXAMPLE 2

Cut pieces of copy paper were dipped in all the Case solutions, andtaken out and allowed to be dried in the atmosphere; any piece of papermaintained flexibility, had a flat and smooth surface, and was onlycarbonized without flush over with flame when ignited.

EXAMPLE 3

The 10% solution of the inorganic dissolution aid of Case C (30 g, pH12.5) was mixed with 3 g of boric acid and heated to 60° C. as describedabove. The solution became transparent and the pH thereof was 8.5.Further, 3 g of boric acid (6 g in total) was mixed and then the pHbecame 5.4 and the solution became transparent. Further mixing of boricacid will decrease the pH down to 4 and the adjustment will be possible.

EXAMPLE 4

The 10% solution of the inorganic dissolution aid B (30 g, pH13.5),described in the above Example 1, was warmed to 70° C., and the additionamount of anhydrous borax (obtained from Soviet Union, 99% pure) wasincreased in the order of 3 g, 6 g, 9 g, and the solution wastransparent at every step of increase. The final pH was 13.5.

EXAMPLE 5

To the 10% solution of the inorganic dissolution aid B in the precedingExample, warmed to 40° C., the boric acid used in the preceding Examplewas added in the increasing order of 3 g, 6 g, 9 g, 12 g, and atransparent solution was obtained. The final pH was 6.2 and the finalsolubility was 40%.

EXAMPLE 6

A stainless steel vessel was charged with 1,000 cc of water, 300 g ofgranular metallic silicon of 5 to 25 mm in grain size was put in thevessel, and additionally, 75 g of sodium fluoride and 100 g of causticsoda were added as dissolution accelerators. Warming at 40° C. wascontinued, but the reaction heat exceeded 90° C. Under stirring, theelapsed time of 2 hours led to a specific gravity of 1.45 and atransparent solution, the pH being 13. The solid content weight of thehydrate was 450 g, while the amount of the dissolution accelerator was175 g, and subtraction of 10% of the hydrated water reveals that about220 g of the metallic silicon was dissolved.

EXAMPLE 7

To 30 g of industrial ethanol, 96% sulfuric acid, 38% nitric acid and35% hydrochloric acid each was added in 2 wt % and mixed to prepare analcohol solution. To this solution, 100 g of the water-soluble inorganiccompound of the preceding Example 6 was added and mixed gently. Thebleeding mixed with alcohol was removed and about 70 to 80 g of aviscous substance was obtained.

The pH was 10.6 to 11. When the mineral acids each was mixed in 1 wt %in the above described Example, the pH of the residual substance wasaround 11.5.

EXAMPLE 8

To 1,000 cc of water, a metal (metal silicon, 97% pure) and an inorganicsubstance (borax decahydrate, 98% pure) were added in sum total of 500g, and the inorganic dissolution accelerator (sodium fluoride+causticsoda) was added in varying mixing ratio, the solution was maintained at40° C. or above and stirred and heated for one hour, and then cooled;the resulting specific gravities are shown below. TABLE-1 Case A Case BCase C Case D Case F Metal, metal 400 g 400 g 400 g 400 g 400 g siliconInorganic 50 g 50 g 70 g 100 g 0 substance, borax decahydrate Inorganic75 g 120 g 140 g 170 g 280 g dissolution accelerator Sodium 25 g 70 g 70g 70 g 180 g fluoride (Sodium nitrite) Caustic soda 50 g 50 g 70 g 100 g100 g Water 1500 g 1500 g 1500 g 1500 g 1500 g pH/20° C. 11.5  11.2 11.07 11.5  10.8  Specific  1.27  1.46  1.64  1.84  1.48 gravityCollected 270 g 464 g 640 g 940 g 480 g solid content

Results:

-   -   a. Increase of the inorganic dissolution accelerator increases        the collected amount of the solid content: Cases A to D.    -   b. Increase of the sodium fluoride ratio increases the collected        amount of the solid content: Cases B to D.    -   c. Increase of the caustic soda ratio leads to increase in the        collected amount of the solid content: Cases C and D.    -   d. Increase of the inorganic substance solubility leads to        increase in the collected amount of the solid content: Case D.    -   e. When the amount of the dissolution accelerator is kept within        50% in relation to the substance to be dissolved, a transparent        solution is obtained.

Even when sodium phosphite, sodium sulfite or sodium nitrite was used inplace of sodium fluoride in the above described experiments, no changewas observed in the general tendency of the results.

Additionally, even when caustic potash was used in place of causticsoda, no change was observed in yield, but the yields were decreasedwhen a lithium salt was used.

Evaluation of borax as a dissolution accelerator revealed that themaximum addition amount in relation to metal silicon was 270/400=67.5%,and similar evaluation for sodium fluoride gave 70/400=17.5% and thatfor caustic soda, 100/400=25%.

Borax hardly soluble in water and other dissolution accelerators weredissolved without leaving any residual.

FIG. 2 shows the X-ray analysis chart for the product of Case A inExample 8. The chart shows no crystal peaks, indicating that the samplewas amorphous. The measurement was made by Shimadzu Techno-Research Inc.

Table 2 shows the pH values, specific gravities and Si: Na ratios foramorphous highly water-soluble inorganic compounds. TABLE-2 Element etc.1 2 3 4 Sio₂ (X) 60. 60.5 65.2 60.2 Na₂O (Y) 38 15.7 19.9 22 B₂O₃ 22.814.9 16.5 NaF 2 1.5 1.3 Specific gravity 1.5 1.28 1.35 1.45 pH 12.6 10.910.8 12. Molar ratio X/Y 1.58 3.85 3.27 2.73A substance with low pH is high in Si/Na ratio.

EXAMPLE 9

The case in which sodium sulfite was used in the preceding Example A isdenoted by A-MS, the case in which sodium nitrite was used by A-MO, thecase for sodium phosphite by A-MP; to 100 g of industrial denaturedethanol, sulfuric acid (96%), nitric acid (38%), phosphoric acid (86%)and hydrochloric acid (35%) each was added in 1 to 1.5 wt %; and to 30 gof the solution thus obtained, 100 g of A-MS, A-MO or A-MP was added andstirred gently, and the bleeding produced by alcohol dehydration wasremoved. The yields were in the order of A-MS>A-MO>A-MP, falling withinthe range from 70 to 82 g. The pH values were 10 to 10.4. In a previousinvention, with pH of 11 or lower, compounds were broken down toprohibit embodiment.

The combination of A-hydrochloric acid resulted in the pH 10 andformation of a transparent starch syrup like substance.

EXAMPLE 10

The high concentration aqueous inorganic compound in the precedingExample having low pH was low in plasticity and became brittle. Heatingthe compound to 40° C. or above to dehydrate the alcohol resulted in theincreased viscosity and plasticity, which permitted the formation ofsheets of 0.2 mm to 2 mm in thickness, namely, of any optionalthickness. Additionally, heating resulted in molding and solidification.

EXAMPLE 11

The pH value of the high concentration aqueous inorganic compound ofExample 6 was 13; 100 g of the compound was mixed in 30 g of industrialethanol containing 35% hydrochloric acid in 2 wt %, and then the pHvalue was 9.6. The bleeding was removed, and the alcohol was removed bywarming, yielding a transparent starch syrup like substance.

The alcohols able to be used include products with various boilingpoints falling in the range from methyl alcohol to glycerin. Withethyleneglycol, a substance of increased viscosity was obtained whichwas transformed into a product with generated plasticity when heated.

EXAMPLE 12

The metal in Example 8 was replaced with a 99% pure aluminum wiremanufactured by Nikkeikin Co. (Nippon Light Metal Co.). The viscositywas decreased compared to the case where metal silicon was used, butsimilarly a high concentration aqueous inorganic compound was obtained.As described above, similar treatment with either alcohol or alcoholcontaining acid yielded a high concentration aqueous inorganic compoundthat had a satisfactory fluidity and a low pH value. The strength of thehardened substance obtained therefrom by dehydration under heatingtended to become lower as compared to that achieved when metal siliconwas used.

Products with pH of 11 or lower tended to be easily manufactured.

EXAMPLE 13

As for the product in Example 6, in the case where the pH was 11.5 orlower, the ratio between the metal component, for example, Si and thealkali component was such that Si:Na>2.5 as an analytical value, andwater resistance was generated when hardened under heating at 200° C. orabove.

EXAMPLE 14

When the pH values of the high concentration aqueous inorganic compoundsof the present invention were 11 or lower, the analytical values thereofwere such that Si:Na>3, as shown in a separate table (Table 2).

EXAMPLE 15

The method of making the ratio Si:Na be 3 or more can include a methodin which addition of a soluble metal component is adopted. Whenfeldspars, diatomites and zeolites are calcined at about 1,000° C. andthen cooled, these are transformed into soluble silica components. Whenin addition to these, for example, radiolite (diatomite manufactured byShowa Chemical Industry Co., Ltd.) was added in 10 wt % to the 45%solution with pH 13 of the above described Example 6, the ratio Si:Nabecame 3 or more; 30 g of the solution was put in a paper cup and heatedfor 3 minutes in a 500 W microwave oven, and then hardening occurred;water was poured into the cup so as for the hardened substance tosubmerge in the water, and the cup was allowed to stand for 7 days,revealing that the strength was maintained and water resistance wasdemonstrated.

Amorphous silica containing substances such as glass, pozzolan and whitecarbon can also be utilized. Heating at 300° C. or above for molding andhardening led to high strength.

EXAMPLE 16

To the high concentration aqueous inorganic compound of 11.4 in pH and1.22 in specific gravity of Example 12, a substance containing aluminain 80% or more such as kaoline and bauxite, calcined at 900° C. to betransformed into soluble alumina, was added and mixed; then the usableperiod of time was sufficiently long, and hardening by dehydrationoccurred when heated at 250° C. To the hardened substance, water waspoured as described above and being allowed to stand confirmed waterresistance and no deterioration phenomenon.

EXAMPLE 17

A magnesia cement (5% or above) containing MgO was added to a solidcontent of the products according to the present invention having the pHvalue ranging from 4 to 13; then, the cement acted as hardening agent toharden the high concentration aqueous inorganic compounds.

EXAMPLE 18

The present inventors disclosed, in U.S.A. Patent No. 3,915,724, themechanism in which the cement strength composition, ettringite, isgenerated in large quantity by an anhydrite (calcined anhydrous gypsumCaSO₄—F) prepared by calcining gypsum added with CaF₂ in 1 wt %, asfollows: the anhydrite accelerates the dissolution rates and dissolutionamounts of the hydrate components in cement particularly such ashemihydrate gypsum and dihydrate gypsum at an ambient temperature; theanhydrite accelerates the elution of the alumina component when heatedeven if the gypsum component is in a condition of supersaturation; andthe anhydrite accelerates the reaction between the gypsum component andthe alumina component, both increased in solubility to highconcentrations. It is well known in the art that cement contains alkalimetals and alkaline earth metals as constituents in a few percents byweight; Table 3 shows the chemical components (1) and the strengths (2)generated by normal temperature curing after setting by heating at 70°C. for a portland cement (TSC-PC) and an alumina cement (TSC-AC) thatare mixed with the above described CaF₂ containing anhydrite. As can beseen from Table 3, the portland cement (TSC-PC) and alumina cement(TSC-AC) according to the present invention are rapid heat curecompositions.

As comparative examples, the chemical components and generated strengthfor a commonly used portalnd cement are shown in the bottom row of eachtable.

RO₂ refers to an alkali metal. TABLE-3 Chemical components described inthe above (1) and characteristics of the cements Fineness ResidueSpecific Blaine % on 88μ Components (wt %) Sample gravity Value SieveIgloss Insol CaO SiO₂ Al₂O₃ SO₃ Fe₂O₃ RO₂ Total TSC-PC 3.01 4500 0.6 3.60.9 53.8 10.0 13.6 14.4 2.2 1.3 99.8 TSC-AC 3.04 4200 0.4 0.1 — 38.4 3.748.7 5.8 1.4 1.8 99.9 Portland 3.15 3100 1 0.4 0.3 64.7 21.4 5.3 2.0 3.31.4 98.5 cement Compressive strength and bending strength described inthe above (2) JIS Workable Mortar Time Transverse Strength (kg/cm²)Compressive Strength (kg/cm²) Sample S/C W/C (min.) 1^(H) 1^(D) 7^(D)28^(D) 1^(H) 1^(D) 7^(D) 28^(D) TSC-PC 2 0.65 240 44 63 78 85 149 283442 460 TSC-AC 2 0.65 350 55 77 81 90 165 306 409 438 Portland 2 0.65170 — 12 40 65 — 32 210 380 cement

It is well known in the art that cement contains a few percents byweight of Na₂O as a composition.

Additionally, it has been revealed that the B, Mg, Zn, Cr, Cd and Pbcomponents, in addition to the F component, have some operationaleffects.

The operational effects revealed in the present invention are shown inFIG. 3, which is a graph showing the relations between the heatingtemperature and the quantities of the eluted components for the abovedescribed anhydrite containing a fluoride (calcined anhydrous gympsumCaSO₄—F).

The above described calcined anhydrous gypsum CaSO₄—F displays somespecial operational effect during heating treatment. The specialoperational effect is described in U.S.A. Patent No. 3,915,724. FIG. 3is a logarithmic graph collecting the results obtained as follows: ananhydrite containing a fluoride accelerated the dissolution of thehydrate components of a quick heat hardening cement, and theacceleration condition was examined while heating by taking the samplesevery hour, stopping the reaction using alcohol, and analyzing thecomponents in the samples. There was shown a condition that the fluorideaccelerated the elution of the alumina component in the presence ofalkaline Ca, in contrast to the accepted theory that at normaltemperature, the elution of the Ca and SO₃ components is accelerated toa supersaturation condition, and when heated, gypsum is supersaturatedand regulates the elution of the alumina component.

The logarithmic graph shows, as can be seen therefrom, the conditionthat coexistence of alkali metal and alkaline earth metal with thecalcium fluoride described in the present Example accelerates theelution of the alumina component to a high concentration. The maincement component is either CaO.SiO₂ (Cao:1 to 3) or CaO.Al₂O₃ (CaO: 1 to4), and hence the elution of CaO and Al₂O₃ is naturally accompanied bythe elution of the Si component to a high concentration.

EXAMPLE 19

In 100 g of the strongly alkaline product of 1.46 in specific gravityand 13 in pH of Example 6, 10 g of amorphous silica was mixed, and themixture was heated in a microwave oven for a rather long period of time.Another mixture of the same composition was heated for 10 minutes in anelectric furnace at an elevated temperature of 500° C., yielding aninorganic foam. As described above, the ratio Si:Na was 3 or more, andhence the water immersion test revealed no deterioration, and the waterresistance was generated. The specific gravities were 0.15 and 0.2.

EXAMPLE 20

To 100 g of the product B of Example 8, 1 to 15 g of isocyanuricmelamine was added, and the mixture thus obtained was heated in amicrowave oven for hardening with foaming; the obtained foam was subjectto the water immersion and water resistance tests. The mixing of 5 g ormore generated the water resistance.

EXAMPLE 21

With 300 g of the strongly alkaline product of 1.46 in specific gravityand 13 in pH used in Example 19, 100 g of ethanol containing 1.5 g ofhydrochloric acid was mixed, and the bleeding was removed, yielding 240g of a transparent solution.

With this solution, 1 to 25 g of cyanuric acid was kneaded, yielding aplastic substance suitable for sheet formation. The kneading in 5 wt %,accompanied by heating with foam at 250° C., generated the waterresistance.

EXAMPLE 22

The plastic substances obtained in Examples 21 and 22 were transformedinto either granules or pellets, and air dried, and thus a product wasobtained the surface of which was hard but in the interior of whichwater was retained. The product was placed in a silicon rubber mold andhot-pressed at 300° C., and thus a plate of 0.2 in specific gravityfilled in the mold was able to be molded. The pellet was transformedinto a foam when heated in a paper cup for 2 to 5 minutes even afterbeing allowed to stand for one month.

Now, description will be made of the noncombustible organoinorganicfoam.

It is well known in the art that silanol and siloxane compounds havecrystallization water structures more resistant to breakdown at hightemperatures than those in cement and gypsum. The amorphous highconcentration aqueous inorganic compound of the present invention has acharacteristic that the water molecule peaks still remain even at 800°C. or above according to the FTIR analyses. The thermal decompositiontemperatures of synthetic resins range from 300 to 400° C., and hencesynthetic resins do not come to catch fire and be combusted with thedecomposition gases thereof if the temperature elevation is suppressedendothermically to the above described range from 300 to 400° C. whenheated. This is the reason for the use of magnesium hydroxide. Thepresent invention provides a foam film formed thereon as in caramelizingsugar when heated, and the film formation is evidence for polymerformation; as for the molecular weight measurement method for Sicompound, although this is not an absolute method, here can be cited theTMS (trimethylsilyl) method developed by DuPont Co., according to which,the molecular weight of the present compound containing Si component wasfound to be 4,800 in relation to the molecular weight of 140 allotted toliquid glass No. 1. As for the boron B based compounds, no measuredmolecular weights are available. The presumed structures of thesecompounds are as follows:

-   [Si based amorphous high concentration aqueous compounds] Alkali    metal salts of silanols Si₂[H_(6-n)OH_(n)] and siloxane H₃SiOSiH₃.-   [Boron B based amorphous high concentration aqueous compounds]    Boric acid compounds B₂[H_(6-n)H_(n)].N, N denoting an alkali or    alkaline earth metal, and n being 1 to 5. As presumed above, these    are amorphous aqueous metal compounds that can be referred to as    “ol” compounds. Accordingly, these compounds were able to be mixed    with carboxylic acids and “ol” compounds having OH groups. Urethane    resin is a convenient resin that can be made through foaming at    normal temperature by mere addition of such a curing agent as TDI    and DDI to the main material polyol (inclusive of denatured    products), and thus displays cushion property. However, urethane    evolves biocidal, toxic gases and black smoke when combusted, and    accordingly it has been classified as a pollutant resin.

The inorganic hardened substances exhibit no flexibility even thoughthey are foams. Thus, there has been demand for pollution-free andcushioned foams or sheets that are made by combining organic andinorganic materials.

If addition of the dehydrated powder of an amorphous high concentrationaqueous inorganic compound of the present invention to urethane resincan yield a composite material in which cushion property is generated inan inorganic substance and an organic substance is transformed into apollution-free form, both inorganic and organic substance can serve toimprove the convenience. The present invention has achieved this.

The cases where Si based materials are used: (a) (b) (c) (d) (e) Polyol100 100 100 100 100 Si based powder 70 40 20 60 40 Antimony 5 5 5 5Melamine cyanurate 5 3 10 10 Special graphite 5 10 Curing agent (TDI,DDI) 70 50 60 70 80

-   -   Cushion property was found independent of polyol and foam volume        due to the blended curing agent.    -   No black smoke was evolved when combusted using a Bunsen burner.    -   (a) cleared the USA aviation standard FAA of 60 second        combustion.    -   (d) and (e) exhibited no dropping and no black smoke evolution        even without using graphite.    -   In the present experiment, the use of graphite (Nippon Kasei        Chemical Co.) did not cause any change in foaming ratio.    -   The urethane resin used in the experiment was of a semirigid        type available at a DIY shop.

According to the Building Standard Law of the Ministry of Constructionof Japan, heat insulating materials used for fireproof construction arerequired to be noncombustible matters; hitherto, the standard was notable to be satisfied without using graphite. And they evolved blacksmoke and toxic gases.

The present inventors have obtained the results that the use of theboron B based amorphous highly water-soluble compounds of the presentinvention permits manufacturing white materials which have foam volumeslarger than that obtained with urethane resin alone and the addition ofthe above described substance as additive to urethane resin does notcause cost increase. The use of urethane leads to formation of soft andflexible foams which do not evolve black smoke when combusted.

To 100 parts of urethane main material of polyol, 100 to 500 parts byweight were added, but no flow value was generated, yielding nopracticability.

In order to overcome this problem, there was used a B based compound(abbreviated as PHN) of the present invention that is a productcontaining solid content to a high concentration of 40% or above. Forsake of accuracy, water was added to a boron B based product heated at200° C. (a) (b) (c) (d) (e) (f) Polyol 100 100 100 100 100 100 PHN 150200 300 400 500 600 Water 30 100 150 200 250 400 DDI 100 55 100 100 100120 Foam volume 350 300 380 400 430 450

-   -   Oil burner test revealed no black smoke evolution, no dropping,        and no afterflame in any case.    -   In any case, combustion at 750° C. for 20 minutes in an electric        furnace left 50 to 70% of solid component and showed the results        close to those for noncombustible matter.    -   No fire retardant was added.    -   Flowability was satisfactory so that application to two-liquid        discharge device is possible.    -   Curing for drying and removing moisture was needed after        foaming.    -   Degree of hardness was increased after curing.

The results show that a noncombustible foam is obtained though foamingat an ambient temperature, thereby employing it as a noncombustible,heat insulating material suitable for a fire-resistant panel.

Industrial Applicability

For the purpose of obtaining inorganic polymers capable of replacingorganic polymers, the present invention has been able to developamorphous highly water-soluble inorganic compounds that are transformedto be pollution-free when combusted and disposed of, by making naturaland synthetic metals and inorganic substances soluble in water in highconcentrations. It has been found that an inorganic dissolutionaccelerator, which forms a composite by combining alkaline metals andalkaline earth metals, and one or more types compounds selected fromfluorides, boric acid, borax, mineral acids and mineral “ous” acids andsalts thereof, has the action to dissolve natural and synthetic metalsand inorganic substances in the aqueous solution so as to be transformedinto amorphous highly water-soluble inorganic compounds, and accordinglyto transform into compounds. Consequently, inorganic polymers are formedand lead to the action effect that the polymers, when heated, aredehydrated, boiled with foam, made to form film, softened andplasticized, hardened and molded with formed film. The inorganic foamsbecome noncombustible and durable heat insulating materials, return tosoil when dumped after pulverization, so that the inorganic foams arefree from pollution, can achieve energy saving and resource saving, andcan replace urethane and polystyrene foam that cause combustionpollution and disposal pollution.

1-20. (canceled)
 21. An inorganic dissolution promoter, comprising: atleast one of a fluoride, a mineral acid, a mineralous acid, a mineralacid salt, a mineralous acid salt, and a boric acid compound; and atleast one of an alkali metal and a substance containing an alkalinemetal, wherein the inorganic dissolution promoter causes one of silicon(Si), aluminum (Al), boron (B) and a compound of one of Si, Al and B,present in water to be dissolved at a concentration which is at leastequal to than a known concentration to produce an amorphous highlywater-soluble inorganic compound.
 22. An amorphous highly water-solubleinorganic compound, obtained by mixing at least one of silicon (Si),aluminum (Al), boron (B), and a compound of at least one of Si, Al, andB present in water with the inorganic dissolution promoter according toclaim 21, and heating the mixture to at least 40° C.
 23. An amorphoushighly water-soluble inorganic compound transformable into awater-resistant hardened substance when heated, the amorphous highlywater-soluble inorganic compound having a pH of not greater than 11.5and a solid content of at least 50% and being obtained by a methodcomprising: mixing an aqueous solution of an amorphous highlywater-soluble inorganic compound which is obtained by mixing at leastone of silicon (Si), aluminum (Al), boron (B), and a compound of atleast one of Si, Al, and B present in water, with the inorganicdissolution promoter according to claim 21; and heating the mixture toat least 40° C., the aqueous solution having a pH of at least 12, withan alcohol comprising a mineral acid; and removing the water and thealcohol from the resulting mixture.
 24. An amorphous highlywater-soluble inorganic compound transformable into a water-resistanthardened substance when heated, the amorphous highly water-solubleinorganic compound having a pH of not greater than 11.5 and a solidcontent of at least 50% and being obtained by: mixing an aqueoussolution of an amorphous highly water-soluble inorganic compound whichis obtained by mixing at least one of silicon (Si), aluminum (Al), boron(B), and a compound of at least one of Si, Al, and B present in water,with the inorganic dissolution promoter according to claim 21; andheating the mixture to at least 40° C., the aqueous solution having a pHof at least 12, with at least one of cyanuric acid and melamineisocyanurate; and removing the water and the alcohol from the resultingmixture.
 25. The amorphous highly water-soluble inorganic compoundtransformable into a water-resistant hardened substance when heatedaccording to claim 23, wherein the metallic component of one of silicon(Si), aluminum (Al), and boron (B) is at least 2.5 times higher in molarratio than the alkali metal component.
 26. A solvent-free inorganicfoam, produced by a method comprising: heating the amorphous highlywater-soluble inorganic compound according to claim 22 to 100° C. to900° C.; dehydrating the inorganic compound by evaporation resulting totransform the inorganic compound into a plasticized film-formingsubstance; and further transforming the substance into a film having apressure resistance strength during evaporation.
 27. A solvent-freeinorganic foam, produced by a method comprising: heating the amorphoushighly water-soluble inorganic compound transformable into awater-resistant hardened substance according to claim 23 to 100° C. to900° C.; dehydrating the inorganic compound by evaporation resulting totransform the inorganic compound into a plasticized film-formingsubstance; and further transforming the substance into a film having apressure resistance strength during evaporation.
 28. An inorganic moldedprecursor, which is made as one of a sheet and granular by one ofair-drying and drying the amorphous highly water-soluble inorganiccompound according to claim 22 so as to lower the water content to notgreater than 30%, the precursor being heated to form a plasticized filmas a solvent-free inorganic foam.
 29. An inorganic molded precursor,which is made as one of a sheet and granular by one of air-drying anddrying the amorphous highly water-soluble inorganic compoundtransformable into a water-resistant hardened substance according toclaim 23 so as to lower the water content to not greater than 30%, theprecursor being heated to form a plasticized film as a solvent-freeinorganic foam.
 30. A rapid thermosetted hardening composition, producedby adding the inorganic dissolution promoter according to claim 21 to achemical compositional compound of one of portland cement and aluminacement.
 31. A fire-retardant organic/inorganic composite foam, producedby a method comprising: adding, to a polyol compound as a main componentof urethane, at least one of the amorphous highly water-solubleinorganic compound according to claim 22 in an amount of at least 20 wt% with respect to the polyol compound, together with a deoxidizing fireretardant; and adding a curing agent to cause the resulting mixture tobe highly foamed and cushioned.
 32. A fire-retardant organic/inorganiccomposite foam, produced by a method comprising: adding, to a polyolcompound as a main component of urethane, at least one of the amorphoushighly water-soluble inorganic compound transformable into awater-resistant hardened substance according to claim 23 in an amount ofat least 20 wt % with respect to the polyol compound, together with adeoxidizing fire retardant; and adding a curing agent to cause theresulting mixture to be highly foamed and cushioned.
 33. The inorganicdissolution promoter according to claim 21, wherein said alkali metalcomprises at least one of Na, K, Li and Ca.
 34. The inorganicdissolution promoter according to claim 21, wherein said fluoridecomprises sodium fluoride.
 35. The inorganic dissolution promoteraccording to claim 21, wherein said inorganic dissolution promotercomprises a composition of sodium fluoride and caustic acid.
 36. Theinorganic dissolution promoter according to claim 21, wherein saidsubstance containing an alkaline metal comprises at least one of causticacid and caustic potash.
 37. The inorganic dissolution promoteraccording to claim 21, wherein said at least one of a fluoride, amineral acid, a mineralous acid, a mineral acid salt, a mineralous acidsalt, and a boric acid compound comprises at least one of sodiumfluoride, sodium phosphite, sodium sulfite, a feldspar, a diatomite, azeolite, kaoline, bauxite and anhydrite.
 38. The inorganic dissolutionpromoter according to claim 21, wherein said substance containing analkaline metal comprises at least one of an alkali metal salt of asilanol and an alkali metal salt of siloxane.
 39. The inorganicdissolution promoter according to claim 21, wherein said boric acidcompound comprises the formula:B₂[H_(6-n)OH_(n)]M wherein M comprises at least one of an alkali earthmetal and an alkaline earth metal, and wherein n is between 1 and 5.